Grain growth in ultrafine-grained copper processed by severe plastic deformation

摘要

Grain growth in ultrafine-grained (UFG) copper during isothermal annealing and heating at a constant rate was studied by TEM, DSC and microhardness measurements. Three stages of thermal structure evolution in UFG copper were identified. These stages are connected with partial relaxation of the defects, migration of non-equilibrium grain boundaries and grain growth. The values of the activation energy in Stage II and Stage III were estimated.